1. Field of the Invention
The present invention relates to a universal serial bus (USB) plug, and more particularly to a USB plug with contacts formed at its bottom and top sides thus allowing the USB plug to electrically insert into a standard USB port in more than one position.
2. Description of Related Art
Peripheral products for personal computers such as keyboards, mice, printers, scanners, CCD cameras, digital cameras as well as MP3 players are becoming increasingly important everyday tools to people. In the past, conventional parallel or serial ports were able to satisfy consumers' demands but then became inadequate due to so many peripherals being required for daily operations. Hence, the universal serial bus (USB) protocol was developed as a universal data transmission interface between personal computers and peripheral products.
The USB protocol supports useful functions such as hot plug as well as plug and play. The versatility provided by the USB protocol means that all USB products can be easily installed and operated. Further, a single USB port can be shared by a maximum quantity of 127 different devices. In comparison to the conventional USB 1.1 protocol, a new USB 2.0 protocol not only retains normal transmission modes (1.5 Mbits/s and 12 Mbit/s) and supports the prior USB 1.1 protocol, but also provides a higher speed data transmission (480 Mbits per second).
Whether using the conventional or present USB protocols, the same specification for USB architecture is employed. The architecture of the present USB plug is designed to be inserted in a USB port in only a single direction so that contacts formed on the USB plug and the USB port can correspondingly touch to each other. If the USB plug is not correctly aligned with the USB port it is not able to be inserted properly since a plastic platform formed in the USB port will block the plug.
For some particular USB products, the limitation that the USB plug can only be linked into the port with a particular direction is very inconvenient. For example, with reference to FIG. 6, a memory card (60) is integrated with a USB plug (61) for connection to a USB port (62) on a panel. However, other serial or parallel ports (63) adjacent to the USB port (62) may abut against an edge of the memory card (60) so that the plug (61) will be blocked at the outside of the USB port (62). If the two sides of the USB plug (61) both have contacts formed thereon, the USB plug (61) can be successfully linked to the port (62) just by turning the memory card (60) as well as the USB plug (61) over.
Therefore, the invention provides a novel USB plug to obviate the aforementioned problem.